Manual sander

ABSTRACT

A manual sander includes a handle and a fixed abrasion surface to which the handle is attached. At least one foldable abrasion surface is connected to the fixed abrasion surface by a hinge. The handle is manipulable to maintain the fixed abrasion surface and the foldable abrasion surfaces in an open configuration in which the fixed abrasion surface and the foldable abrasion surfaces are substantially coplanar. The handle is also manipulable to enable the foldable abrasion surface to fold about the hinge to form a folded configuration in which the fixed abrasion surface and the foldable abrasion surface form a bent surface.

FIELD OF THE INVENTION

The present invention relates to sanding. More particularly, the presentinvention relates to a manual sander.

BACKGROUND OF THE INVENTION

Various types of sanding devices are available to enable smoothing of asurface by motion of an abrasive surface. Typically, the abrasivesurface includes a preformed piece of grit-covered sandpaper that isattached to a permanent surface of the sanding device. Thus, a wornpiece of sandpaper may be replaced with a fresh piece, or sandpaper withone grit sized may be replaced with sandpaper of another (e.g., finer orcoarser) grit size.

For example, a manual sander or sanding block may include a handle and aflat, typically rectangular, surface to which a similarly shaped pieceof sandpaper may be attached. When holding the device by the handle, auser may rub the sandpaper surface over the surface to be smoothed.

A power sander includes a motorized or pneumatically operated mechanismthat may be operated to move the sandpaper with a predetermined motion.For example, the motion may be circular (e.g., as with a disk sander orflap sander), linear (e.g., as with a belt, drum, or straight-linesander), or otherwise (e.g., orbital, with a combination of motions, orotherwise). The sandpaper pieces may be circular, rectangular,triangular, or otherwise shaped.

SUMMARY OF THE INVENTION

There is thus provided, in accordance with an embodiment of the presentinvention, a manual sander including: a handle; a fixed abrasion surfaceto which the handle is attached; and at least one foldable abrasionsurface that is connected to the fixed abrasion surface by a hinge,wherein the handle is manipulable to maintain the fixed abrasion surfaceand the at least one foldable abrasion surface in an open configurationin which the fixed abrasion surface and the at least one foldableabrasion surface are substantially coplanar, and is manipulable toenable the at least one foldable abrasion surface to fold about thehinge to form a folded configuration in which the fixed abrasion surfaceand the at least one foldable abrasion surface form a bent surface.

Furthermore, in accordance with an embodiment of the present invention,the handle includes an axis that is attached to the fixed abrasionsurface to enable lateral rotation of the handle relative to the fixedabrasion surface.

Furthermore, in accordance with an embodiment of the present invention,the handle is configured to be laterally rotated in a forward directionto maintain the open configuration, and in a backward direction that isopposite the forward direction to enable the folded configuration.

Furthermore, in accordance with an embodiment of the present invention,the rotation in the forward direction causes an end of the handle toextend beyond the hinge.

Furthermore, in accordance with an embodiment of the present invention,the handle includes a locking structure that is configured to engagecooperating structure to lock the handle to maintain the fixed abrasionsurface and the at least one foldable abrasion surface in the openconfiguration.

Furthermore, in accordance with an embodiment of the present invention,the cooperating structure is located on a foldable abrasion surface ofthe at least one foldable abrasion surface.

Furthermore, in accordance with an embodiment of the present invention,the locking structure is at an end of the handle and the cooperatingstructure is located at an edge of the at least one foldable abrasionsurface that is furthermost from the hinge to which that foldableabrasion surface is connected.

Furthermore, in accordance with an embodiment of the present invention,the locking structure and the cooperating structure are configured tolock the handle when a longitudinal axis of the handle is substantiallyperpendicular to the hinge.

Furthermore, in accordance with an embodiment of the present invention,the locking structure includes an indentation in a base of the handle,and the cooperating structure includes a locking tab on the at least onefoldable abrasion surface.

Furthermore, in accordance with an embodiment of the present invention,the fixed abrasion surface and the at least one foldable abrasionsurface form a substantially circular abrasion surface when in the openconfiguration.

Furthermore, in accordance with an embodiment of the present invention,the sander includes a retaining mechanism that is configured to retainthe fixed abrasion surface and the at least one foldable abrasionsurface in a folded configuration.

Furthermore, in accordance with an embodiment of the present invention,the retaining mechanism includes a retaining structure on the handle,and cooperating retaining structure that is located on a foldableabrasion surface of the at least one foldable abrasion surface.

Furthermore, in accordance with an embodiment of the present invention,the retaining structure includes a ferromagnetic plate and thecooperating retaining structure includes a magnet.

Furthermore, in accordance with an embodiment of the present invention,the cooperating retaining structure is located on a locking tab of theat least one foldable abrasion surface.

Furthermore, in accordance with an embodiment of the present invention,the retaining mechanism is configured to retain the at least onefoldable abrasion surface substantially perpendicular to the fixedabrasion surface.

Furthermore, in accordance with an embodiment of the present invention,the handle includes a socket to enable attachment of an extensionhandle.

Furthermore, in accordance with an embodiment of the present invention,the extension handle includes an eccentric knob.

Furthermore, in accordance with an embodiment of the present invention,an attachment stem of the extension handle and the socket includecooperating guiding structure to maintain an orientation of theextension handle relative to the socket.

Furthermore, in accordance with an embodiment of the present invention,the hinge includes a groove.

There is further provided, in accordance with an embodiment of thepresent invention, method for preparing a manual sander for smoothing awork surface, the method including: providing the manual sander, thesander including an abrasion surface that includes a fixed abrasionsurface and at least one foldable abrasion surface that is connected tothe fixed abrasion surface by a hinge; and manipulating a handle that isconnected to the fixed abrasion surface to maintain attached the fixedabrasion surface and the at least one foldable abrasion surface in anopen configuration in which the fixed abrasion surface and the at leastone foldable abrasion surface are substantially coplanar, and attachinga piece of sandpaper to the substantially coplanar surfaces; ormanipulating the handle to enable the at least one foldable abrasionsurface to fold about the hinge to form a folded configuration in whichthe fixed abrasion surface and the at least one foldable abrasionsurface form a bent surface; placing the piece of sandpaper on the worksurface such that the piece of sandpaper is bent to match a contour ofthe work surface; and placing the abrasion surface on the sandpaperwhile folding the at least one foldable abrasion surface to form a bentabrasion surface that is attached to the bent piece of sandpaper.

BRIEF DESCRIPTION OF THE DRAWINGS

In order for the present invention, to be better understood and for itspractical applications to be appreciated, the following Figures areprovided and referenced hereafter. It should be noted that the Figuresare given as examples only and in no way limit the scope of theinvention. Like components are denoted by like reference numerals.

FIG. 1A schematically illustrates a manual sanding device in accordancewith an embodiment of the present invention.

FIG. 1B schematically illustrates the manual sanding device shown inFIG. 1A, with the sanding surface visible.

FIG. 2A schematically illustrates the manual sanding device shown inFIG. 1A when locked in an open configuration.

FIG. 2B schematically illustrates the unlocking of the manual sandingdevice shown in FIG. 1A.

FIG. 2C schematically illustrates the manual sanding device shown inFIG. 1B when folded.

FIG. 3 schematically illustrates an extension handle for the manualsanding device shown in FIG. 1A.

FIG. 4 schematically illustrates components for assembly into the manualsanding device shown in FIG. 1A.

FIG. 5A schematically illustrates a side view of attaching a piece ofsandpaper to the manual sander shown in FIG. 2A when in an openconfiguration.

FIG. 5B schematically illustrates a folded configuration of the manualsander for smoothing an inside corner.

FIG. 5C schematically illustrates preparation of the manual sander shownin FIG. 1A for smoothing an outer corner.

FIG. 5D schematically illustrates preparation of the manual sander shownin FIG. 1A for smoothing a convexly curved surface.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those of ordinary skill in the artthat the invention may be practiced without these specific details. Inother instances, well-known methods, procedures, components, modules,units and/or circuits have not been described in detail so as not toobscure the invention.

Although embodiments of the invention are not limited in this regard,the terms “plurality” and “a plurality” as used herein may include, forexample, “multiple” or “two or more”. The terms “plurality” or “aplurality” may be used throughout the specification to describe two ormore components, devices, elements, units, parameters, or the like.Unless explicitly stated, the method embodiments described herein arenot constrained to a particular order or sequence. Additionally, some ofthe described method embodiments or elements thereof can occur or beperformed simultaneously, at the same point in time, or concurrently.Unless otherwise indicated, the conjunction “or” as used herein is to beunderstood as inclusive (any or all of the stated options).

In accordance with an embodiment of the present invention, a manualsander is convertible to an open configuration that is suitable forsmoothing a substantially flat work surface, or to a foldedconfiguration that is suitable for smoothing a joint or corner betweentwo substantially flat work surfaces. For example, an abrasion surfaceof the manual sander may include one or more foldable sections or wingsthat enable the abrasion surface to be configured to form a singlesubstantially flat and coplanar abrasion surface, or to form a bentabrasion surface.

The manual sander includes a handle and the abrasion surface. The sandermay be manipulated by a user who is holding the handle to rub theabrasion surface over a work surface (e.g., wood, drywall, or anothertype of work surface) that is to be smoothed. For example, the abrasionsurface may be inherently abrasive (e.g., roughened or coated with anabrasive grit or other abrasive material, or may incorporate a metalrasp or similar surface), or may be configured to hold a piece ofsandpaper substantially flat against a mounting surface. As used herein,sandpaper may refer to any type of replaceable or disposable sheet-likeabrasive material. The sandpaper may be held to the mounting surface byone or more clips or other holding structure, or may be held by anadhesive. The adhesive may include an adhesive material (e.g., adhesivetape, glue, or other sticky or tacky surface), or may include amechanical adhesive surface (e.g., a hook-and-loop fastener such asVelcro™)

The abrasion surface includes a fixed section and one or more foldablesections. For example, the foldable sections may be connected to thefixed section by a hinge. As used herein, a hinge refers to anysubstantially straight connection between two sections or surfaces thatenables relative folding or rotation of the sections or surfaces aboutthe axis of the hinge. The hinge may include a groove, scoring, or othermodification in an otherwise continuous piece of material (e.g., aplastic disk) that facilitates folding relative to one another of tworegions on opposite sides of the hinge. Alternatively or in addition, ahinge structure may enable folding of two pieces of a rigid material(e.g., metal, wood, or another rigid material) relative to one another.

The handle is attached to the fixed section of the abrasion surface in amanner that allows for manipulation of the handle relative to the fixedsection. The attachment may enable rotation or translation of the handlerelative to the fixed section. However, the attachment may be such thatthe handle cannot be readily removed from the fixed section withoutdisassembling, breaking, bending, or distorting the fixed section, thehandle, or both. For example, an axis of the handle may be attached tothe fixed section in a manner that enables rotation of the handlerelative to the fixed section while not enabling ready removal thehandle from the fixed section. As another example, a tab or extension ofthe handle may extend into a slot of the fixed section, or a tab orprojection from the fixed section may extend into a slot of the handle,in a manner that enables sliding or translation of the handle relativeto the fixed section but not ready removal of the handle from the fixedsection.

The handle may be manipulated to lock or hold the abrasion surface suchthat the abrasion surface is maintained in an open configuration. Forexample, the handle may be mounted on or attached to the fixed sectionof the abrasion surface. The handle may be configured to rotate relativeto the fixed section, or to translate or slide relative to the fixedsection. When the handle is in one rotation or translationconfiguration, locking structure of the handle may engage cooperatingstructure on a foldable section of the abrasion surface. When thecooperating structure is engaged, one or more of the foldable sectionsmay be fixed in an open configuration. For example, a rigid structure ofthe handle may block any folding of the foldable section. Alternativelyor in addition, the motion of the handle may activate or trigger amechanical or actuated locking mechanism, e.g., on the fixed section, toengage cooperating structure, e.g., on a foldable section.

When in the open configuration, the fixed and foldable sections of theabrasion surface are substantially coplanar configuration to form asubstantially flat abrasion surface. For example, a flat abrasionsurface may be used to smooth a substantially flat or gently curvedsurface (e.g., a surface whose curvature is sufficiently small so as toenable the substantially flat abrasion surface to be manipulated andrubbed over so as to smooth the gently curved surface).

The handle may be manipulated to enable a folded configuration of theabrasion surface. For example, the handle may be rotated or translatedso as to disengage the locking structure from the cooperating structure(or to cause or enable a locking mechanism to disengage from cooperatingstructure).

When the configuration of the abrasion surface is unlocked, one or morefoldable sections of the abrasion surface may be folded inward. As usedherein, inward folding refers to folding a foldable section in adirection that is away from the abrasive surface of the section. Wheninwardly folded, the abrasion surface may take the form of two or moresections that present a convex fold or bend. When the convex fold of theabrasion surface is aligned parallel to a concave junction between twosurfaces (e.g., at an internal corner where two flat walls meet) andinserted into the concave junction, the convex abrasive surface may berubbed (e.g., parallel to the junction, or otherwise) to smooth thesurfaces at the concave junction.

As another example, the foldable sections of the abrasion surface may befolded outward (opposite the inward folding, e.g., in the direction ofthe abrasive surface of the foldable section). When folded outward, thesurface may conform at least approximately to the form of a convexsurface (e.g., the outer surface of a cylindrical workpiece).

The manual sander may include retaining mechanism structure that isconfigured to retain the abrasion surface in one or more foldedconfigurations. For example, the retaining mechanism may includeretaining structure that is located on the handle. The retainingstructure on the handle may be configured to engage cooperatingretaining structure on one or more of the foldable sections. Forexample, the retaining structure and the cooperating retaining structuremay include parts of a snap fastener, a magnet and a ferromagneticplate, hook-and-loop fasteners, clips, or other retaining structure.

The retaining structure may be configured to retain a fold between twosections of the abrasion surface at a hinge in a particularconfiguration. For example, the retaining structure may maintain thefold at a right angle, or at another fixed angle. Alternatively or inaddition, the retaining structure may be configured (e.g., with two ormore stops or other structure) to maintain the fold at two or morepredetermined fixed angles. Alternatively or in addition, the retainingstructure may be configured (e.g., with a clamp or other structure) toenable a user to fix the fold at an arbitrarily selected angle (e.g.,within a predetermined range of angles).

In order to lock the abrasion surface in an open configuration, anyfolded sections may be unfolded until all sections of the abrasionsurface are substantially coplanar. Any retaining structure that isretaining any of the sections in a folded configuration may be caused torelease the folded sections. For example, the retaining structure (e.g.,in the form of a magnet, snap fastener, hook-and-loop fasteners, orother types of fastening structure) may be configured to release when anunfolding force or torque is applied to the folded sections. In somecases, the retaining structure (e.g., in the form of a clip, latch, orother type of fastening structure) may be released prior to unfoldingthe folded sections. When all sections of the abrasion surface areunfolded so as to be substantially coplanar, the handle may bemanipulated (e.g., rotated or translated) to lock the sections in a flatconfiguration.

The handle may include a grip that is configured to facilitate graspingand manipulation of the handle, manual sander, or both, by a user. Thehandle may include structure to enable attachment of an extensionhandle. For example, the handle may include one or more sockets intowhich an extension handle may be inserted. The extension handle may beof fixed length and shape, may be telescoping, may be bendable, or mayhave another form.

FIG. 1A schematically illustrates a manual sanding device in accordancewith an embodiment of the present invention. FIG. 1B schematicallyillustrates the manual sanding device shown in FIG. 1A, with the sandingsurface visible.

Manual sander 10 is shown in an unlocked configuration. Manual sander 10includes abrasion base 12. In the example, shown, abrasion base 12 is inthe form of a disk with a fixed section 16 and two foldable sections 18.In other examples, an abrasion base may include a single foldablesection, or three or more foldable sections.

Fixed section 16 includes fixed abrasion surface 22. Each foldablesection 18 includes a foldable abrasion surface 24. In the configurationthat is shown in FIGS. 1A and 1B, fixed abrasion surface 22 and foldableabrasion surfaces 24 are coplanar, so as to function as a single flatabrasion surface 13. In the example shown, flat abrasion surface 13 iscircular. In other examples, abrasion base 12 and flat abrasion surface13 may have other shapes (e.g., rectangular, polygonal, oval, or anothershape).

Fixed abrasion surface 22 and each foldable abrasion surface 24 may beat least partially covered with a hook-and-loop fastener surface. Thehook-and-loop fastener surface may enable attachment of a piece ofsandpaper or other abrasive material (whose rear surface is similarlyprovided with a cooperating hook-and-loop fastener surface) to fixedabrasion surface 22 and foldable abrasion surfaces 24. For example, adisk-shaped piece of sandpaper may be attached to a circular flatabrasion surface 13, as in the example shown. Alternatively or inaddition, separate pieces of sandpaper, e.g., each shaped to cover fixedabrasion surface 22 or foldable abrasion surface 24, may be attached tothe correspondingly shaped fixed abrasion surface 22 or foldableabrasion surface 24.

Alternatively or in addition, fixed abrasion surface 22 and foldableabrasion surface 24 may be provided with other structure for holding apiece of sandpaper. For example, part or all of one or both of fixedabrasion surface 22 or foldable abrasion surface 24 may be covered withan adhesive coating. Alternatively or in addition, abrasion base 12 mayinclude one or more clips, straps, suction cups, or other structure forholding a piece of sandpaper to flat abrasion surface 13.

Each foldable section 18 of abrasion base 12 is connected to fixedsection 16 at a hinge 20. Each hinge 20 enables its connected foldablesection 18 to fold in at least one direction relative to fixed section16.

In the example shown, hinge 20 includes a linear groove in a piece ofplastic from which abrasion base 12 is formed (e.g., by a molding ormachining process). For example, hinge 20 in the form of a groove mayhave a V-shaped cross section. The V-shape of the cross section of thegroove may be configured to enable inward folding (toward sander handle11, and away from foldable abrasion surface 24) of the connectedfoldable section 18 toward fixed section 16 (e.g., so as to close thewalls of the groove inward to close the V-shape). The extent of inwardfolding may be limited by the shape of the groove, by grip 14, or both.Hinge 20 in the form of a groove may also enable outward folding offoldable section 18, such that fixed abrasion surface 22 and foldableabrasion surface 24 form a concave surface (e.g., for smoothing a convexsurface such as a cylindrical, spherical, spheroid, exterior cornerbetween two flat sides, or other convex surface). Alternatively or inaddition, hinge 20 may include another type of jointed or flexiblestructure that connects foldable section 18 to fixed section 16. Forexample, the jointed or flexible structure may be mechanically attached(e.g., using an adhesive, welding, soldering, screws, bolts, rivets, orotherwise) to foldable section 18, fixed section 16, or both.

Manual sander 10 includes handle 11. Handle 11 includes grip 14 andhandle base 21. In the example shown, grip 14 is shorter than handlebase 21. In other examples, grip 14 and handle base 21 may havesubstantially similar length.

Handle 11 may be configured to facilitate grasping and manipulation ofmanual sander 10. For example, grip 14 may be shaped in a manner (e.g.,an arched shape, as shown, or another shape) that facilitates firm andcomfortable grasping of handle 11. Grip 14 may include surfaces that arecovered with a non-slip material that facilitates gripping of handle 11.For example, grip 14 may include side panels 19 and one or more fingergrooves 17. One or more side panels 19 and finger grooves 17 may becovered or coated with a non-slip material.

Handle 11 may be configured so as to facilitate grasping andmanipulation of manual sander 10 when manual sander 10 is in differentconfigurations. For example, in the open configuration (e.g., as shownin FIGS. 1A, 1B and 2A), handle 11 may be grasped primarily using sidepanels 19 of grip 14. When manual sander 10 is in a folded configuration(e.g., as shown in FIGS. 2C), handle 11 may be grasped primarily usingfinger grooves 17 of grip 14.

Handle 11 may include an extension handle socket 33, shown covered bysocket cap 34. Extension handle socket 33 may be configured to attach toan end of an extension handle. For example, extension handle socket 33may include internal threading, projections, sockets, or other structureto enable firm attachment of an extension handle to extension handlesocket 33.

An extension handle (e.g., eccentric extension handle 40, as shown inFIG. 3) may be ergonomically designed for convenient handling of manualsander 10.

In some cases, an extension handle may enable manipulation of manualsander 10 when holding grip 14 by hand is difficult, inconvenient, ornot possible. For example, an extension handle may be used to manipulatemanual sander 10 to smooth a work surface that would otherwise beinaccessible (e.g., more distant than the length of the user's arm,recessed within a narrow space or cavity, around a corner, or otherwiseinaccessible when handheld). An extension handle may be telescoping orbendable in order to facilitate access to the work surface.

Manual sander 10 may include one or more structures to facilitatestorage of manual sander 10. For example, manual sander 10 may includehanger 32 to enable hanging on a hook or peg. In the example shown,hanger 32 may be foldable inward when manual sander 10 is in use so asto reduce or eliminate interference with manipulation of manual sander10. For example, when hanger 32 is folded inward, hanger 32 may engagehanger latch 31 (visible in FIGS. 2A and 2B) to retain hanger 32 in itsfolded state. Alternatively or in addition, hanger 32 may be slidable orretractable into an appropriate cavity of manual sander 10.Alternatively or in addition, other structure to enable storage ofmanual sander 10 may be included. Such other storage structure mayinclude one or more hooks, magnets, holes, or other structure tofacilitate storage.

Handle 11 may be manipulated to lock manual sander 10 in an openconfiguration (where fixed abrasion surface 22 and foldable abrasionsurfaces 24 are substantially coplanar), or to enable inward folding ofone or more foldable sections 18.

In the example shown, handle 11 may be rotated about handle axis 15.Handle axis 15 may enable lateral rotation (e.g., parallel to fixedabrasion surface 22) of handle 11 relative to fixed section 16 ofabrasion base 12. In the configuration shown in FIG. 1A, handle 11 isoriented so as not to impede inward folding of either foldable section18 about its connected hinge 20.

When handle 11 is rotated from the parallel configuration shown in FIG.1A through at least a minimum angle (e.g., to the configuration shown inFIG. 2B), part of handle base 21 of handle 11 may extend beyond hinge20. When part of handle base 21 extends beyond hinge 20, the part ofhandle base 21 that extends beyond hinge 20 may impede or prevent inwardfolding of either foldable section 18 about its connected hinge 20.

In the example shown in FIG. 1A, handle 11 may be laterally rotated in aforward direction (clockwise in the example shown) in order to lockabrasion base 12 in an open configuration. Forward lateral rotation ofhandle 11 about handle axis 15 when foldable sections 18 are unfolded(as shown in FIG. 1A) may cause locking structure in the form of alocking indentation 30 at an end (along the longitudinal axis) of handlebase 21 of handle 11 to engage cooperating locking structure in the formof locking tab 28 on foldable section 18. In the example shown, lockingindentation 30 includes an indentation at either end of handle base 21and each foldable section 18 includes a locking tab 28.

Other configurations of locking structure and cooperating structure maybe used. For example, the locking structure may include a tab and thecooperating structure may include a latch or indentation. The lockingstructure, cooperating structure, or both, may include a magnet, alatch, or other type of structure.

When locking indentation 30 engages locking tab 28, inward folding offoldable section 18 about hinge 20 may be prevented. For example,locking indentation 30, locking tab 28, or both may be elastic (e.g.,made of a resilient plastic that may temporarily distort or bend whensubjected to a force), spring loaded, or otherwise resiliently bendableor distortable such that exertion of torque (e.g., in the clockwisedirection in the example shown) will locking tab 28 to insert intolocking indentation 30. The elasticity or resilience may prevent lockingtab 28 from disengaging from locking indentation 30 in the absence ofexertion of an opposite (e.g., counterclockwise) torque. Alternativelyor in addition, handle 11, foldable section 18, or both may have otherstructure that may operate to impede or prevent inward folding offoldable section 18.

Engagement of locking indentation 30 by locking tab 28 may also preventoutward folding of foldable section 18 about hinge 20. For example,locking tab 28 may be shaped (e.g., with an enlarged distal end, orotherwise) such that engagement of locking indentation 30 by locking tab28 does not allow locking tab 28 to slide relative to lockingindentation 30. Alternatively or in addition, friction between lockingindentation 30 and locking tab 28 may prevent sliding of locking tab 28relative to locking indentation 30.

Alternatively or in addition, locking structure on the handle may beconfigured to engage cooperating structure on fixed section 16. Forexample, the locking structure on the handle may be located at a part ofthe handle that is proximal to the ends of the handle, e.g., near arotation axis of the handle.

Retaining structure may be provided to retain abrasion base 12 in afolded configuration. For example, handle 11, e.g., grip 14 of handle11, may include handle retaining structure 26. When a foldable section18 is folded inward toward handle 11, handle retaining structure 26 mayengage foldable section retaining structure 29. Foldable sectionretaining structure 29 may be located on a locking tab 28, or elsewhereon foldable section 18. For example, one of handle retaining structure26 and foldable section retaining structure 29 may include a magnet,while the other includes a ferromagnetic plate, tab, or other structure.Alternatively or in addition, both handle retaining structure 26 andfoldable section retaining structure 29 may include magnets (e.g., withappropriate polarity to enable retention). Alternatively or in addition,handle retaining structure 26 and foldable section retaining structure29 may include cooperating mechanical retaining structure (e.g., maleand female parts of a snap connector, a latch and structure that may beengaged by the latch, hook-and-loop fastener surfaces, adhesivesurfaces, or other mechanical retaining structure).

Alternatively or in addition to rotation of handle 11, a handle may beconfigured to be moved or slid translationally in order to preventinward folding of foldable sections 18. For example, an end of atranslatable handle may be configured in the form of a wedge that may beinserted into cooperating structure (e.g., a wedge-like slot orindentation) on one or more foldable sections. Locking structure may beprovided to prevent unintended sliding away from the configuration thatprevents inward folding of foldable sections 18.

FIG. 2A schematically illustrates the manual sanding device shown inFIG. 1A when locked in an open configuration.

In the example shown, when manual sander 10 is locked in an openconfiguration, a longitudinal axis of handle 11 (e.g., the longitudinalaxis of handle 11 representing an axis along the longest lateraldimension of handle 11, e.g., extending between both locking structures30 on handle 11) is oriented substantially perpendicular to (the foldingaxis of each of) hinges 20. The length of handle base 21 of handle 11extends beyond the width of fixed section 16 of abrasion base 12 tocover the width of each foldable section 18. Thus, in this orientation,handle base 21 overlaps each foldable section 18 and prevents inwardfolding of foldable section 18 about its connected hinge 20. In theexample, shown, the length of handle base 21 is sufficiently close tothe radius of abrasion base 12 so as to cover most of the width of eachfoldable section 18.

When the longitudinal axis of handle 11 is rotated to a locking angle,locking indentation 30 on handle base 21 of handle 11 may engage lockingtab 28 of foldable section 18. Thus, the orientation of handle 11relative to abrasion base 12 may be locked. For example, engagement oflocking tab 28 by locking indentation 30 may prevent further forwardlateral rotation of handle 11 (e.g., clockwise in the example shown)relative to abrasion base 12 beyond the locked orientation. Engagementof locking tab 28 by locking indentation 30 may impede or preventunintentional backward lateral rotation of handle 11 away from thelocked orientation (e.g., counterclockwise in the example shown). Forexample, backward lateral rotation of handle 11 may require deliberateapplication of torque to handle 11 relative to abrasion base 12. Inorder to enable the backward rotation of handle 11, the applied torquemay be sufficient so as to disengage locking indentation 30 from lockingtab 28.

In the example, shown, handle 11 is rotated to the locking angle whenthe longitudinal axis of handle 11 is oriented substantiallyperpendicular to hinge 20. Locking indentation 30 is located on eitherend of handle base 21, and locking tab 28 is located at the furthermostedge of foldable section 18 from its hinge 20 (e.g., as measured byperpendicular distance from hinge 20).

Alternatively or in addition, locking structure on handle 11 may beconfigured to engage structure (e.g., similar to locking tab 28) onfoldable section 18 when the longitudinal axis of handle 11 is orientedat a non-perpendicular oblique angle to hinge 20. The rotation of handle11 to the oblique locking angle may be require rotation of handle 11through an angle that is less than 90° (an acute angle), or through anangle that is greater than 90° (an obtuse angle).

When locked in an open configuration, fixed abrasion surface 22 andfoldable abrasion surfaces 24 form a substantially coplanar andcontiguous flat abrasion surface 13. The area of the contiguous flatabrasion surface 13 may enable efficient smoothing of a flat (or gentlycurving) work surface. For example, the full area of a disk-shaped pieceof sandpaper that is attached to flat abrasion surface 13 may be exposedas a single contiguous surface. A user may grasp grip 14 of handle 11(e.g., by one or more of side panels 19 and finger grooves 17, orotherwise) and manipulate manual sander 10 to smooth a work surface.Engagement of locking tabs 28 by locking indentation 30 may impede orprevent unintentional folding of foldable sections 18.

In some situations, manual sander 10 may be unlocked from the openconfiguration to enable inward folding of one or foldable sections 18.

FIG. 2B schematically illustrates the unlocking of the manual sandingdevice shown in FIG. 1A.

In the configuration shown, handle 11 has been laterally rotatedbackward (e.g., counterclockwise in the example shown) to disengage eachlocking indentation 30 from its corresponding locking tab 28. Forexample, a backward torque may have been applied to handle 11 relativeto abrasion base 12. Since the ends of handle base 21 if handle 11continue to extend beyond each hinge 20 to its attached foldable section18, inward folding of foldable section 18 is impeded.

Further backward lateral rotation of handle 11 may enable free inwardfolding of foldable sections 18.

FIG. 2C schematically illustrates the manual sanding device shown inFIG. 1B when folded.

In the example, shown, foldable section 18 b is partially folded inwardabout hinge 20 b. As a result of the inward folding, foldable abrasionsurface 24 b is not coplanar with fixed abrasion surface 22. Continuedinward folding of foldable section 18 b about hinge 20 b, e.g., untilfoldable section 18 is completely folded inward toward handle 11, maybring foldable section retaining structure 29 adjacent to handleretaining structure 26. Foldable section retaining structure 29 may thenengage handle retaining structure 26 to retain foldable section 18 b ina fully folded configuration.

Retaining foldable section 18 b in a fully folded configuration mayfacilitate use of manual sander 10 in a fully folded configuration.

In the example shown, foldable section 18 a is fully folded inward abouthinge 20 a such that foldable abrasion surface 24 a is substantiallyperpendicular to fixed abrasion surface 22. For example, foldablesection retaining structure 29 of foldable section 18 a may be engagedby the corresponding handle retaining structure 26 on handle 11.

Fixed abrasion surface 22 together with foldable abrasion surfaces 24 aand 24 b form a convexly bent abrasion surface 13′. Alternatively, oneor both of foldable abrasion surfaces 24 a and 24 b may be foldedoutward to form a concavely bent abrasion surface, or bent partlyconcavely (e.g., at one hinge 20) and partly convexly (e.g., at anotherhinge 20).

Thus, manual sander 10 may be used to smooth work surfaces at a corner.In the example, shown, hinge 20 a may be inserted into a corner wheretwo substantially perpendicular work surfaces, e.g., two walls of a roomor of another enclosure, meet. Application of pressure to manual sander10 while moving manual sander 10 parallel to hinge 20 a within thecorner may concurrently smooth the sections of both of the work surfaceswhere they meet at the corner.

For example, socket cap 34 may be opened and an extension handle may beinserted into the exposed extension handle socket 33. For example,structure on the extension handle (e.g., one or more of externalthreading, tabs, sockets, or other structure) may engage cooperatingstructure (e.g., internal threading, sockets, tabs, or other cooperatingstructure) within extension handle socket 33. The extension handle maythen be used to manipulate manual sander 10 in a folded configuration.Alternatively or in addition, handle 11 of manual sander 10 may begrasped (e.g., at finger grooves 17 on grip 14, or elsewhere) in orderto manipulate manual sander 10 in a folded configuration.

FIG. 3 schematically illustrates an extension handle for the manualsanding device shown in FIG. 1A.

Eccentric extension handle 40 includes eccentric knob 42. Eccentric knob42 is asymmetrically distributed about the point of attachment, e.g.,attachment stem 46, of eccentric extension handle 40 to extension handlesocket 33. Eccentric extension handle 40 may be configured to enable auser of manual sander 10 to select an orientation of eccentric extensionhandle 40 relative to handle 11 and grip 14. For example, the user mayselect the handle on the basis of, comfort, the position of work surfaceto be smoothed, handedness of the user, or otherwise. Thus, eccentricextension handle 40 may enable ergonomic gripping and manipulation ofmanual sander 10.

Eccentric extension handle 40 may be disassembled into a knob section 41that includes eccentric knob 42 and attachment stem 46, and a knob cover44. Knob cover 44 may be attached to knob section 41 to form eccentricextension handle 40. For example, knob section 41 and knob cover 44 maybe made of plastic and separately formed by a molding process, orotherwise. In some cases, eccentric handle 40 may be made a singleintegral part.

Attachment stem 46 may be inserted into extension handle socket 33 ofhandle 11. The outer diameter or other outer dimension of attachmentstem 46 may be selected to be approximately equal to the inner diameter,or other corresponding dimension, of extension handle socket 33. Thus, apushing force may be applied to attachment stem 46 in order to insertattachment stem 46 into extension handle socket 33. As a result,friction forces may prevent unintentional withdrawal of attachment stem46 from extension handle socket 33 until a pulling force is applied towithdraw attachment stem 46 from extension handle socket 33.

Attachment stem 46 and extension handle socket 33 may be provided withguiding structure. For example, guiding structure on attachment stem 46may include a plurality of stem grooves 47 that are orientedlongitudinally along (e.g., substantially parallel to an axis of)attachment stem 46. Stem grooves 47 may be distributed approximatelyuniformly around the diameter of attachment stem 46, or may be otherwisedistributed. Extension handle socket 33 may include guiding structure inthe form of one or more socket tabs 48. For example, extension handlesocket 33 may include two socket tabs 48 one opposite sides of extensionhandle socket 33. Each socket tab 48 is configured with a size,orientation, and shape to engage (e.g., insert into) a stem groove 47 ofattachment stem 46 when attachment stem 46 is inserted into extensionhandle socket 33. Alternatively, extension handle socket 33 may includea plurality of distributed socket tabs 48 while attachment stem 46includes one or more stem grooves 47. Alternatively or in addition,attachment stem 46 may be provided with one or more tabs while extensionhandle socket 33 is provided with one or more grooves. Other guidingstructure (e.g., attachment stem 46 and extension handle socket 33having corresponding polygonal cross sections, or other guidingstructure) may be provided.

Thus, the guiding structure (e.g., stem grooves 47 and socket tab 48, orother guiding structure) may limit the orientation of eccentricextension handle 40 relative to handle 11 to a limited number oforientations. The guiding structure may maintain an orientation ofeccentric extension handle 40 relative to extension handle socket 33 andhandle 11 during use of manual sander 10 by preventing unintentionalrotation of eccentric extension handle 40 relative to handle 11 andmanual sander 10. The guiding structure may increase friction betweenattachment stem 46 and extension handle socket 33 so as to furtherprevent unintentional withdrawal of attachment stem 46 from extensionhandle socket 33.

FIG. 4 schematically illustrates components for assembly into the manualsanding device shown in FIG. 1A.

Socket cap 34 may be inserted into extension handle socket 33 of grip 14when no extension handle is inserted into extension handle socket 33.Insertion of socket cap 34 into extension handle socket 33 mayfacilitate comfortable gripping of grip 14 when no extension handle. Forexample, when socket cap 34 is inserted into extension handle socket 33,a user who is gripping grip 14 may feel a smooth surface, rather than anopening that may chafe or otherwise cause discomfort to the user.

In the example shown, each handle retaining structure 26 may include aferromagnetic plate (e.g., made of stainless steel or anotherferromagnetic material) that is inserted into and held by a plate slot27 on grip 14. Each handle retaining structure 26 may include a magnetthat may be inserted into each magnet socket 49 and into each lockingtab 28 in each foldable section 18 of abrasion base 12.

Flat abrasion surface 13 may be covered with (e.g., with an appropriateglue or other adhesive) with sandpaper attachment surface 50. Sandpaperattachment surface 50 may enable attachment of sandpaper or another typeof sheet-like abrasive material to flat abrasion surface 13. Forexample, sandpaper attachment surface 50 may include a surface of ahook-and-loop fastener that is configured to attach to a cooperatinghook-and-loop fastener on the sandpaper. In the example shown, thesandpaper may include a typical commercially available sandpaper diskfor attachment to a disk sander. The rear surface of such a sandpaperdisk may be covered with a loop surface of the hook-and-loop fastener.In this case, a front surface of sandpaper attachment surface 50 (e.g.,the surface that is configured to face the work surface and away fromabrasion base 12) may be covered with a hook surface of thehook-and-loop fastener.

Sandpaper attachment surface 50 may include a single piece that isshaped (circular in the example shown, or otherwise shaped) to coversubstantially all of flat abrasion surface 13. Alternatively or inaddition, sandpaper attachment surface 50 may include separate sectionsthat are each shaped to cover part of flat abrasion surface 13. Forexample, central sheet section 52 of sandpaper attachment surface 50 maybe shaped so as to cover fixed abrasion surface 22 Similarly, each endsheet section 54 of sandpaper attachment surface 50 may be shaped tocover a foldable abrasion surface 24. A sandpaper attachment surface 50may be otherwise divided into sections.

In order to use manual sander 10 to smooth a work surface, a user mayexecute a method for preparing manual sander 10 for use.

FIG. 5A schematically illustrates a side view of attaching a piece ofsandpaper to the manual sander shown in FIG. 2A when in an openconfiguration.

When preparing to smooth a flat work surface 64 or gently curving worksurface 66 (e.g., a convex work surface as shown, or, in some cases, aconcave work surface with a radius of curvature that is much larger thanthe diameter of flat abrasion surface 13), handle 11 (represented bygrip 14) may be manipulated to the open configuration shown in FIG. 2A.Sandpaper 60 (e.g., a sandpaper disk or otherwise shaped piece ofsandpaper) may be attached to the resulting coplanar, flat abrasionsurface 13, as indicated by sandpaper attachment motion 62. Manualsander 10 may then be manipulated (e.g., by gripping grip 14 orotherwise) to sand flat work surface 64 or gently curving work surface66.

In some cases, the work surface may include a concavely bent worksurface, such as an inside corner along an inside edge where two flat orgently curved surfaces meet.

FIG. 5B schematically illustrates a folded configuration of the manualsander for smoothing an inside corner.

When a concavely bent work surface is to be smoothed, such as insidecorner surface 68, handle 11 may be manipulated to enable foldableabrasion surface 24 to fold about hinge 20, with sandpaper 60 attached,to form a folded configuration in which fixed abrasion surface 22 andfoldable abrasion surfaces 24 form a convexly bent abrasion surface 13′.Manual sander 10 with convexly bent abrasion surface 13′ may then bemanipulated to smooth inside corner surface 68.

In the example shown, inside corner surface 68 is in the form of a rightangle. In this case, handle retaining structure 26 and foldable sectionretaining structure 29 may retain bent abrasion surface 13′ so as toform a right angle. In some cases, the sides that meet to form an insidecorner surface may meet at an obtuse angle. In that case, a foldablesection 18 may be partially folded inward (e.g., similar to foldablesection 18 b in FIG. 2C).

In some cases, sandpaper 60 may be placed on the work surface prior toattachment to bent abrasion surface 13′. For example, the front surface(e.g., the abrasive surface) of a piece of sandpaper may be insertedinto inside corner surface 68, or placed over a convexly bent or curvedsurface. An appropriately shaped abrasion surface of manual sander 10may then be pressed onto the rear side of the piece of sandpaper toattach the piece of sandpaper to the abrasion surface (e.g., via ahook-and-loop fastener, an adhesive, or otherwise, and in a mannersimilar to attachment of outwardly bent abrasion surface 13″ tosandpaper 60 as described below).

FIG. 5C schematically illustrates preparation of the manual sander shownin FIG. 1A for smoothing an outer corner.

In the example shown, outside corner surface 70 forms a right angle. Inother cases, outside corner surface 70 may form an acute or obtuseangle. Sandpaper 60 may be placed over outside corner surface 70, withthe front (abrasive) side of sandpaper 60 facing outside corner surface70.

Manual sander 10 may be moved toward sandpaper 60 with sander attachmentmotion 72. Concurrently, one or more of foldable sections 18 may befolded outwardly from manual sander 10 with outward folding 73 to forman outwardly bent abrasion surface 13″ whose contour substantiallymatches the form of sandpaper 60 on outside corner surface 70. In thismanner, outwardly bent abrasion surface 13″ may attach to sandpaper 60.Typically, sandpaper 60 is not appreciably elastic (e.g., cannot bestretched to an extent that would be detectible by the unaided eye).Therefore, if the bond between sandpaper 60 and outwardly bent abrasionsurface 13″ is sufficiently strong, sandpaper 60 may function topreserve the form of outwardly bent abrasion surface 13″.

FIG. 5D schematically illustrates preparation of the manual sander shownin FIG. 1A for smoothing a convexly curved surface.

In the example shown, convexly curved surface 74 is circular(cylindrical). In other cases, convexly curved surface 74 may beelliptical or otherwise curved, or may be in the form of a corrugation.Sandpaper 60 may be placed over convexly curved surface 74, with thefront side of sandpaper 60 facing convexly curved surface 74.

Manual sander 10 may be moved toward sandpaper 60 with sander attachmentmotion 76. Concurrently, one or more of foldable sections 18 may befolded outwardly from manual sander 10 with outward folding 77 to forman outwardly bent abrasion surface 13″ whose contour substantiallymatches (e.g., partially circumscribes) the form of sandpaper 60 onconvexly curved surface 74 (e.g., at lines or points where outwardlybent abrasion surface 13″ is tangent to sandpaper 60 on convexly curvedsurface 74). In this manner, outwardly bent abrasion surface 13″ mayattach to sandpaper 60. Typically, when sandpaper 60 is not appreciablyelastic and the bond between sandpaper 60 and outwardly bent abrasionsurface 13″ is sufficiently strong, sandpaper 60 may function topreserve the form of outwardly bent abrasion surface 13″.

Different embodiments are disclosed herein. Features of certainembodiments may be combined with features of other embodiments; thuscertain embodiments may be combinations of features of multipleembodiments. The foregoing description of the embodiments of theinvention has been presented for the purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise form disclosed. It should be appreciated bypersons skilled in the art that many modifications, variations,substitutions, changes, and equivalents are possible in light of theabove teaching. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents will now occur to those of ordinary skill in the art. It is,therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the invention.

1. A manual sander comprising: a handle; a fixed abrasion surface towhich the handle is attached; and at least one foldable abrasion surfacethat is connected to the fixed abrasion surface by a hinge, wherein thehandle is manipulable to maintain the fixed abrasion surface and said atleast one foldable abrasion surface in an open configuration in whichthe fixed abrasion surface and said at least one foldable abrasionsurface are substantially coplanar, and is manipulable to enable said atleast one foldable abrasion surface to fold about the hinge to form afolded configuration in which the fixed abrasion surface and said atleast one foldable abrasion surface form a bent surface.
 2. The sanderof claim 1, wherein the handle comprises an axis that is attached to thefixed abrasion surface to enable lateral rotation of the handle relativeto the fixed abrasion surface.
 3. The sander of claim 2, wherein thehandle is configured to be laterally rotated in a forward direction tomaintain the open configuration, and in a backward direction that isopposite the forward direction to enable the folded configuration. 4.The sander of claim 3, wherein the rotation in the forward directioncauses an end of the handle to extend beyond the hinge.
 5. The sander ofclaim 4, wherein the handle comprises a locking structure that isconfigured to engage cooperating structure to lock the handle tomaintain the fixed abrasion surface and said at least one foldableabrasion surface in the open configuration.
 6. The sander of claim 5,wherein the cooperating structure is located on a foldable abrasionsurface of said at least one foldable abrasion surface.
 7. The sander ofclaim 6, wherein the locking structure is at an end of the handle andthe cooperating structure is located at an edge of said at least onefoldable abrasion surface that is furthermost from the hinge to whichthat foldable abrasion surface is connected.
 8. The sander of claim 5,wherein the locking structure and the cooperating structure areconfigured to lock the handle when a longitudinal axis of the handle issubstantially perpendicular to the hinge.
 9. The sander of claim 5,wherein the locking structure comprises an indentation in a base of thehandle, and the cooperating structure comprises a locking tab on said atleast one foldable abrasion surface.
 10. The sander of claim 1, whereinthe fixed abrasion surface and said at least one foldable abrasionsurface form a substantially circular abrasion surface when in the openconfiguration.
 11. The sander of claim 1, further comprising a retainingmechanism that is configured to retain the fixed abrasion surface andsaid at least one foldable abrasion surface in a folded configuration.12. The sander of claim 11, wherein the retaining mechanism comprises aretaining structure on the handle, and cooperating retaining structurethat is located on a foldable abrasion surface of said at least onefoldable abrasion surface.
 13. The sander of claim 12, wherein theretaining structure comprises a ferromagnetic plate and the cooperatingretaining structure comprises a magnet.
 14. The sander of claim 12,wherein the cooperating retaining structure is located on a locking tabof said at least one foldable abrasion surface.
 15. The sander of claim11, wherein the retaining mechanism is configured to retain said atleast one foldable abrasion surface substantially perpendicular to thefixed abrasion surface.
 16. The sander of claim 1, wherein the handlecomprises a socket to enable attachment of an extension handle.
 17. Thesander of claim 16, wherein the extension handle comprises an eccentricknob.
 18. The sander of claim 17, wherein an attachment stem of theextension handle and the socket comprise cooperating guiding structureto maintain an orientation of the extension handle relative to thesocket.
 19. The sander of claim 1, wherein the hinge comprises a groove.20. A method for preparing a manual sander for smoothing a work surface,the method comprising: providing the manual sander, the sander includingan abrasion surface that includes a fixed abrasion surface and at leastone foldable abrasion surface that is connected to the fixed abrasionsurface by a hinge; and manipulating a handle that is connected to thefixed abrasion surface to maintain attached the fixed abrasion surfaceand said at least one foldable abrasion surface in an open configurationin which the fixed abrasion surface and said at least one foldableabrasion surface are substantially coplanar, and attaching a piece ofsandpaper to the substantially coplanar surfaces; or manipulating thehandle to enable said at least one foldable abrasion surface to foldabout the hinge to form a folded configuration in which the fixedabrasion surface and said at least one foldable abrasion surface form abent surface; placing the piece of sandpaper on the work surface suchthat the piece of sandpaper is bent to match a contour of the worksurface; and placing the abrasion surface on the sandpaper while foldingsaid at least one foldable abrasion surface to form a bent abrasionsurface that is attached to the bent piece of sandpaper.